David Silva has been ruled out of Manchester City's clash with Borussia Dortmund and is doubtful for the derby with Manchester United at the weekend on account of a hamstring injury.

The Spanish schemer is a key figure for City, but he could be forced to sit out arguably two of the club's biggest games of the season to date. City need a positive result in Dortmund to stand any chance of reaching the Europa League.

Silva played the entire 90 minutes of the 1-1 draw with Everton in the Premier League at the weekend, but has reported a hamstring complaint that has ruled him out of the Champions League clash with Dortmund.

The midfielder did not travel to Dortmund with the rest of the squad and will be monitored in Manchester ahead of the derby with United on Sunday.

"Silva is not here because he has a hamstring injury and we do not know at the moment if he can recover in time for the derby," City boss Roberto Mancini said. "We will try, but we will have to see."

Assessing his side's chances in Dortmund, Mancini said: "We are a good team, we want to play well and to win. We have bought all the players that are available.

"The players that are here will do everything to win, but it will be difficult as Borussia are one of the best teams in Europe."

United lead City by three points in the Premier League and referee Martin Atkinson has been named as the man in charge of affairs at the Etihad on Sunday.

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